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Ho2[As4O9] : the first ternary catena‐oxotetraarsenate(III) of the lanthanoids
No full textThe pale yellow holmium(III) catena‐oxotetraarsenate(III) Ho2[As4O9] crystallizes needle‐shaped from a CsBr‐flux‐assisted metallothermic reaction between As2O3 and elemental holmium at 875 °C in the monoclinic space group P21/c with the lattice parameters a = 802.98(6) pm, b = 548.83(4) pm, c = 1101.62(9) pm and β = 107.519(3)° for Z = 2. The singular Ho3+ cation is surrounded by seven oxygen atoms in the shape of a capped distorted octahedron [HoO7]11-. These polyhedra link with each other twice via edge and twice via corner to form layers described by the Niggli formula , which spread out parallel to the (100) plane. Both distinct As3+ cations form ψ1‐tetrahedral [AsO3]3- units with three oxygen atoms, which are vertex‐condensed to a catena‐oxotetraarsenate(III) anion [As4O9]6-. All [As4O9]6- groups serve as linkers between the layers, while the stereochemically active free electron pairs at the As3+ cations arrange themselves to create lone‐pair channels along the [010] direction. Furthermore, Raman‐spectroscopic investigations, which frequently show Ho3+ luminescence, and effective coordination number calculations are carried out for the new crystal structure of Ho2[As4O9].Projekt DEA
Comparison of visual highlighting techniques for complex and high-fidelity tasks in VR
No full textDuring our everyday lives, we regularly look for things, performing visual searches. At other times, signs seek to attract our attention. An Augmented Reality (AR)-based assistant system visually highlighting objects of interest would thus prove useful in a variety of situations. But how do we best guide users’ attention? On 2D displays with limited size, simple approaches such as coloring are often sufficient. However, in Augmented and Virtual Reality (VR), targets can be located in any direction, making highlighting more difficult. Many highlighting techniques for use in AR and VR have been proposed to solve this issue. As AR hardware still has some limitations, techniques are frequently evaluated in VR. Yet, these evaluations are often conducted in abstract, small, or static settings. This thesis aims to provide insight into the performance of highlighting techniques in a complex and high-fidelity environment, which users naturally traverse. For this, we analyzed previously proposed approaches. In VR, we implemented four highlighting techniques to compare (Color + Outline, Link, Arrow, and HiveFive). We further provided a high-fidelity virtual city center with various dynamic elements in which to compare the highlighting techniques. Using an Omnidirectional Treadmill, it is possible to traverse this environment while walking naturally. Results of our user study showed that in our high-fidelity environment, Link was the fastest highlighting technique, while Arrow was the slowest. Further, Color + Outline and HiveFive had an increased rate of missed targets. Regarding personal preference, Arrow performed the worst, while the other three were rather popular. Participants also expressed a preference for a combination of in-view and in-situ elements for visual highlighting. This suggests that different highlighting techniques are differently suited for finding objects in complex and high-fidelity environments.In unserem Alltag suchen wir regelmäßig nach Dingen. Oft suchen wir dabei unsere Umgebung visuell ab. In anderen Situationen versuchen Schilder unsere Aufmerksamkeit zu erregen. Ein Augmented Reality (AR)-basierter Assistent, der wichtige Objekte visuell hervorhebt würde sich daher in einer Vielzahl von Situationen als nützlich erweisen. Aber wie lenken wir am besten die Aufmerksamkeit von Nutzern? Auf 2D Bildschirmen mit limitierter Größe reichen dafür meistens einfache Ansätze wie das Einfärben von Objekten. Allerdings ist das in Augmented und Virtual Reality (VR) schwieriger, da Ziele in jeder Richtung liegen können, was das Hervorheben erschwert. Es wurden bereits viele Hervorhebungstechniken für den Gebrauch in AR und VR vorgestellt, um dieses Problem zu lösen. Da AR Hardware immer noch Limitationen aufweist, werden Techniken häufig in VR evaluiert. Jedoch werden diese Auswertungen oft in abstrakten, kleinen oder statischen Umgebungen durchgeführt. Das Ziel dieser Masterarbeit ist es, einen Einblick in den Effekt von Hervorhebungstechniken in einer komplexen und realitätsnahen Umgebung, welche Nutzer naturgemäß durchqueren, zu geben. Zu diesem Zweck haben wir bereits existierende Ansätze analysiert. Wir haben vier Hervorhebungstechniken (Color + Outline, Link, Arrow und HiveFive) in VR implementiert. Weiterhin haben wir eine realitätsnahe virtuelle Innenstadt mit verschiedenen dynamischen Elementen entwickelt, in welcher die Hervorhebungstechniken verglichen werden. Mit Hilfe einer Omnidirectional Treadmill ist es möglich, diese Umgebung natürlich laufend zu durchqueren. Die Ergebnisse unserer Studie haben gezeigt, dass in unserer realitätsnahen Umgebung Link die schnellste und Arrow die langsamste Hervorhebungstechnik war. Außerdem hatten Color + Outline und HiveFive eine erhöhte Rate von verpassen Zielen. In Bezug auf persönliche Preferenz zeigte sich, dass Arrow am schlechtesten abschnitt, während die anderen Drei eher beliebt waren. Beim visuellen Hervorheben drückten die Teilnehmer außerdem eine Präferenz für eine Kombination von in-view und in-situ Elementen aus. All dies deutet darauf hin, dass verschiedene Hervorhebungstechniken verschieden geeignet sind, in komplexen und realitätsnahen Umgebungen Objekte zu finden
CO generation from CO2 using an atmospheric microwave plasma process
No full textWith rising CO₂ levels and climate change, finding alternatives to fossil fuels is essential. One attractive option is converting CO₂ into CO and O₂ via an atmospheric microwave plasma process. This study evaluates conversion and energy efficiency by increasing microwave power and CO₂ flow. Power and CO₂ flow were varied, with conversion measured using Fourier transform‐infrared spectroscopy, mass spectrometry, and gas analysis. A maximum conversion of 21.1 % was achieved at a specific energy input of 1.1 eV molecule -1 , highlighting the potential of this approach for efficient CO₂ utilization
Assessing long-term post-conflict air pollution : trends and implications for air quality in Mosul, Iraq
No full textProlonged conflicts in Iraq over the past four decades have profoundly disrupted environmental systems, not only through immediate post-conflict emissions-such as residues from munitions and explosives-but also via long-term infrastructural collapse, population displacement, and unsustainable resource practices. Despite growing concern over air quality in conflict-affected regions, comprehensive assessments integrating long-term data and localized measurements remain scarce. This study addresses this gap by analyzing the environmental consequences of sustained instability in Mosul, focusing on air pollution trends using both remote sensing data (1983-2023) and in situ monitoring of key pollutants-including PM2.5, PM10, TVOCs, NO2, SO2, and formaldehyde-at six urban sites during 2022-2023. The results indicate marked seasonal variations, with winter peaks in combustion-related pollutants (NO2, SO2) and elevated particulate concentrations in summer driven by sandstorm activity. Annual average concentrations of all six pollutants increased by 14-51%, frequently exceeding WHO air quality guidelines. These patterns coincide with worsening meteorological conditions, including higher temperatures, reduced rainfall, and more frequent storms, suggesting synergistic effects between climate stress and pollution. The findings highlight severe public health risks and emphasize the urgent need for integrated urban recovery strategies that promote sustainable infrastructure, environmental restoration, and resilience to climate change
Implementation strategies for a low-code approach to develop data products
No full textThe preparation of data in a valuable and usable way is crucial for data-driven applications. The paradigm of data products was therefore introduced as a domain-centric, shareable, and valuable unit. To create relevant data products, it is essential to incorporate domain expertise. Consequently, low-code approaches have gained increasing attention, as they facilitate modeling of development steps through a graphical editor. Conceptual frameworks such as LALO and BARENTS address data product development through low-code approaches, but to translate these concepts into practice, a concrete implementation strategy is required. Therefore, different components of BARENTS and LALO and possible existing approaches were examined and discussed. A limitation in the way heterogeneous sources and sinks are connected to the system was identified. Current approaches fail to adequately address the complexity of heterogeneous sources and sinks by not making the connection process sufficiently accessible for domain experts. To address this limitation, an adapter-based approach was introduced in this work, allowing data providers and data consumers to define connections, mappings, and metadata. This ensures that the available data is both understandable and usable. In addition, it enables the involvement of domain experts in the development process. To demonstrate its applicability, a prototype with example implementations and a user interface was developed.Die Aufbereitung von Daten in einer wertvollen und nutzbaren Form ist für datengesteuerte Anwendungen von entscheidender Bedeutung. Das Paradigma der Datenprodukte wurde daher als domänenzentrierte, teilbare und wertvolle Einheit eingeführt. Um relevante Datenprodukte zu erstellen, ist es wichtig, Domänenewissen einzubeziehen. Daher finden Low-Code Ansätze zunehmend Beachtung, da sie die Modellierung von Transformationsschritten durch einen grafischen Editor ermöglichen. Konzeptionelle Arbeiten wie LALO und BARENTS adressieren die Entwicklung von Datenprodukten durch einen Low-Code Ansatz, jedoch ist eine konkrete Implementierungsstrategie erforderlich, um diese Konzepte in die Praxis umzusetzen. Daher wurden verschiedene Komponenten von BARENTS und LALO sowie mögliche bestehende Ansätze untersucht und diskutiert. Dabei wurden bei der Anbindung von heterogenen Quellen und Senken mit dem System fehlende Implementierungsstrategien festgestellt. Aktuelle Ansätze werden der Komplexität heterogener Quellen und Senken nicht ausreichend gerecht, da sie den Verbindungsprozess für Domänenexperten nicht ausreichend zugänglich machen. Um dies zu verbessern, wurde in dieser Arbeit ein adapterbasierter Ansatz eingeführt, der es Datenanbietern und Datenkonsumenten ermöglicht, Verbindungen, Transformationen und Metadaten zu definieren. Dadurch werden die verfügbaren Daten sowohl verständlicher als auch nutzbarer und Experten können in den Entwicklungsprozess mit einbezogen werden. Um die Anwendbarkeit zu demonstrieren, wurde ein Prototyp mit Beispielimplementierung und einer Benutzeroberfläche entwickelt
Rolling on the chip : SARS-CoV‑2 detection by DNA motors
No full textRolosense uses DNA motors for SARS-CoV-2 detection, enabling rapid, smartphone-based testing with high specificity and sensitivity, useful for early diagnosis and outbreak control.Baden-Württemberg StiftungMax-Planck-Gesellschaf
Model-driven engineering for digital twins : a systematic mapping study
No full textDigital twins (DTs) are proliferating in a multitude of domains, including agriculture, automotive, avionics, logistics, manufacturing, medicine, smart homes, etc. As domain experts and software experts both have to contribute to the engineering of effective DTs, several model-driven engineering (MDE) approaches have been recently proposed to ease the design, development, and operation of DTs. However, the diversity of domains in which MDE is currently applied to DTs, as well as the diverse landscape of DTs and MDE applications to DTs, makes it challenging for researchers and practitioners to get an overview of what techniques and artifacts are already applied in this context. In this paper, we shed light on the aforementioned aspects by performing a systematic mapping study on the application of MDE automation techniques, i.e., model-to-model transformation, code generation, and model interpretation, in the context of DTs as well as on the characteristics of DTs including the twinned systems to which these techniques are applied in different domains. We systematically retrieved a set of 189 unique publications, of which 66 were selected for further investigation in this paper. Our results indicate that the distribution of employed MDE techniques (136 applications of automation techniques) is balanced between the different techniques, but there are significant variations for different DT types. With respect to the different domains, we found that even though applications are available in many domains, a small number of domains currently dominate applications of MDE to DTs, i.e., more than half of included papers are in the manufacturing and transportation domains.Johannes Kepler University Lin
Greedy-kernel algorithms for data mapping in multiphysics simulations
No full textData mapping in multiphysics simulation coupling describes the transfer of data between possibly nonconforming meshes. Choosing a numerical approximation method for data mapping is always a trade-off between accuracy and performance. Lower-accuracy methods include, for example, the first-order nearest-neighbour mapping, whereas higher accuracies can often be achieved with a computationally expensive radial basis function interpolation.
We extend the multiphysics coupling library preCICE with a greedy approach to radial basis function interpolation. We implement and evaluate the P- and f-greedy methods, which aim to reduce the size of a radial basis function interpolant using a greedy vertex selection approach. The greedy selection is terminated when a user-defined tolerance for a greedy criterion is reached. We compare this method to the nearest neighbour, as well as a global-direct solution and a partition-of-unity approach to radial basis function mapping.
We find, that the greedy selection process is computationally expensive for small error tolerances. At the same time, we often see an improvement in mapping time compared to a global-direct solution after the interpolant has been constructed in an offline stage. For high error tolerances, a nearest-neighbour mapping is typically the cheaper option. The partition-of-unity method can achieve comparatively small errors for better runtimes.Datenabbildung beschreibt in der Kopplung von Multiphysik-Simulation die Übertragung von Daten zwischen möglicherweise nicht übereinstimmenden Gittern. Bei der Wahl einer numerischen Approximationsmethode für die Datenabbildung muss immer ein Kompromiss zwischen Genauigkeit und Laufzeitkosten eingegangen werden. Zu den Methoden mit geringerer Genauigkeit gehört zum Beispiel das Nearest-Neighbour-Mapping erster Ordnung, während höhere Genauigkeiten oft mit einer rechenaufwändigen Radialbasisfunktionsinterpolation erreicht werden können.
Wir erweitern die Multiphysik-Kopplungsbibliothek preCICE um einen Greedy-Ansatz zur Radialbasisfunktionsinterpolation. Wir implementieren und evaluieren die P- und f-Greedy-Methoden, die darauf abzielen, die Größe einer Interpolante mithilfe eines Greedy-Ansatzes bei der Auswahl von Gitterpunkten zu reduzieren. Die Greedy-Auswahl wird beendet, wenn eine nutzerdefinierte Toleranz für ein Greedy-Kriterium erreicht ist. Wir vergleichen diese Methode mit dem Nearest-Neighbour-Mapping sowie mit einer global-direkten Lösung und einem Partition-of-Unity-Ansatz zur Radialbasisfunktionsinterpolation.
Wir stellen fest, dass der Greedy-Auswahlprozess bei niedrigen Fehlertoleranzen sehr rechenintensiv ist. Gleichzeitig ist oft eine Verbesserung der Abbildungszeit im Vergleich zu einer global-direkten Lösung feststellbar, nachdem die Interpolante in einer Offline-Phase konstruiert wurde. Bei hohen Fehlertoleranzen ist eine Datenabbildung mit dem Nearest-Neighbour-Mapping in der Regel die günstigere Option. Mit der Partition-of-Unity-Methode können vergleichsweise kleine Fehler bei besseren Laufzeiten erreicht werden
Efficacy of personalized feedback in encouraging sustainable washing behavior : evidence from a pilot study in Germany
No full textIntroduction: Reducing household energy consumption through behavioral changes is a key strategy in addressing the emissions driving the climate crisis. Behavioral changes in affluent households toward more sustainable practices can have a significant positive impact. Prior research highlighted the role of individual values and motivational factors in shaping sustainable clusters. A more personalized approach toward encouraging the resulting clusters of people to adopt more sustainable strategies seems promising. Such an approach could incorporate aligned feedback, which has been proven to be a powerful mechanism throughout learning processes.
Method: Over 9 weeks, a pilot study with 50 participants investigated the impact of different types of feedback on washing behavior. The within-subjects design included (1) a baseline condition, (2) feedback on energy consumption (kWh), and (3) feedback on monetary costs per cycle (EUR). Data collection encompassed pre- and post-condition surveys, a final comprehensive survey, and a diary-formatted table. The primary objective was to evaluate the potential for individualization. Asynchronous structured interviews were conducted at the end to explore participants' perceptions and washing behaviors.
Results: While we found effects for the feedback manipulation, we found no differences between user clusters in individual washing behaviors. Furthermore, participants qualitatively reported habitual changes, feeling more knowledgeable about the monetary impacts of specific washing programs and temperatures, and wished for a more accessible preset time function. Most participants expressed willingness to switch to a dynamic energy price if it translated to significant cost savings.
Discussion: Our findings may support the notion that individualized behavior change strategies are promising. In general, these strategies should be easily applicable, cost-effective, and promote habits to be exerted regularly. Arising methodological limitations suggest further research in this domain. From an applied perspective, our research provides valuable insights for designing products, services, and regulations by governments and companies, empowering them to develop more effective strategies for reducing energy consumption.Robert Bosch GmbH, Deutsche Forschungsgemeinschaf
Crystal structure of (N,N',N"-trimethyl-N,N',N"-tris-(1-phenylethyl)- guanidinium hexafluorophosphate), C28H36F6N3P
No full textC28H36F6N3P, monoclinic, P21 (No. 4), a = 9.125(1) Å, b = 14.596(3) Å, c = 11.028(2) Å, β = 102.36(1)°, V = 1434.7 Å3, Z = 2,Rgt(F) = 0.0783, wRref(F2) = 0.1597, T = 293 K